Faunal structure of small mammals (Erinaceomorpha, Soricomorpha, Chiroptera and Rodentia) in two protected areas of the Middle Volga region (European Russia)

Most existing data on the distribution of living organisms are usually contained in various taxonomic publications, checklists and natural history collections. As a result, these data tend to be often difficult to generalize. Biodiversity databases are an effective tool for integrating and assessing this type of information. Our dataset, recently published in GBIF as the Darwin Core Archive, contains up-to-date information on the occurrence of small mammals (hedgehogs, shrews, bats and rodents) in two protected areas of European Russia: the Mordovia Nature Reserve and National Park “Smolny”. The dataset summarizes animal occurrences from our field studies of small mammals using snap traps, mist nets and nature observations during 2018–2023. This database consists of 7950 records of occurrence of small mammals, including 5672 records in the Mordovia Nature Reserve and 2278 records in the National park “Smolny”. Our dataset lists 35 species of small mammals from 21 genera and 9 families. Each occurrence record contains the name of the species, the basis of the record, the age and sex of animal individual, the reproductive state of the females, the location, the date and the authors of the record. All records are georeferenced and published in GBIF for the first time. The species richness of small mammals noted in the protected areas of Mordovia is similar for other regions of European Russia.